As its name implies, a slipper bushing utilizes slippage between mating surfaces of the nonrotatably fixed and rotatable portions of the slipper bushing as a means to permit controlled rotational movement therebetween. Often a lubricant, which may be contained in grooves in one or the other of the mating surfaces, is utilized to lubricate those surfaces in order to decrease the break away torque, i.e. the torque required to overcome the circumferential frictional force between the mating surfaces. It is desirable, therefore, to include an end cap on each axial end of the slipper bushing, which end cap includes an annular flange portion covering the interface of the mating surfaces, in an attempt to eliminate as much as possible any contaminants, for example dirt and the like, from entering into the bushing between the slip surfaces, since such contamination would thereby contaminate the lubricant thereon and undesirably increase the break away torque. One example of such a bushing is disclosed in Chakko U.S. Pat. No. 5,139,244, assigned to the assignee of the present invention, and hereby incorporated by reference herein as if fully set forth in its entirety.
While such a slipper bushing design can prevent at least some of the contaminants, to which a bushing is subjected in its operating environment, from entering therein, improvements in slipper bushing sealing techniques are desirable. However, any such improvements must not increase the break away torque of the slipper bushing to undesirable levels.